Method of producing piston rings



Sept. 4, 1934. w s BAKER 1,972,083

METHOD OF PRODUCING PISTON RINGS Original Filed June 10, l32

Ema/MM r" T /I Patented Sept. 4, 1934 UNITED STATES PATENT OFFICE METHOD OF PRODUCING PISTON RINGS Texas Original application June 10, 1932, Serial No. 616,377. Divided and this application February 10, 1933, Serial No. 656,139

3 Claims. (01. 29156.6)

This invention relates to new and useful improvements in methods of producing piston rings.

One object of the invention is to provide an improved method of producing a one-piece piston ring of the over-lapping gap type.

A particular object of the invention is to provide a method for producing a one-piece piston ring, wherein the overlapping or tongue element is produced from a separate piece of metal and united with the ring so as to become an integral part thereof. The advantage of such a'procedure is that breakage of the tongue is reduced to a minimum and the major portion of the tongue may expand independently of the body of the ring.

Still another object of the invention is to form the tongue of a separate piece of metal and weld it or otherwise permanently fasten it to one end of the ring so as to overhang or project from the same, but at the same time having a substantial portion circumferentially co-extensive with the body of the ring and in contact therewith, thereby assuring a uniform heat flow from the tongue to the body, as well as a substantial support for the tongue. This will prevent crystallization at the point of junction of the tongue with the main body and will also permit a maximum thickness of the tongue, because there will be no saw kerf or tool clearance between the tongue and the ring.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawing, in which the steps of the process are illustrated and wherein:

Figure 1 is a plan view of the split portion of a piston ring blank,

Figure 2 is a similar view showing the ends of 4 the ring formed with grooves for the reception of a tongue,

Figure 3 is a like view showing the tongue in place, prior to securing it to the ring,

Figure 4 is a similar view showing the tongue secured in place,

Figure 5 is an elevation of the split portion of the ring showing it in its spread position,

Figure 6 is an elevation of the same portion showing the ring closed,

Figure 7 is a plan view of the same, and

Figure 8 is a plan view of a complete ring constructed in accordance with the invention, and in its closed position.

This application is filed as a division of my copending application filed June 10, 1932, Serial No. 616,377.

in the end portions of the ring so as to extend circumferentially and inwardly from the ends of the gap. These grooves may extend approximately half the axial thickness of the ring, but are preferably cut inwardly to more than half the radial thickness of the annulus. The grooves may be produced in any suitable manner as by milling, or otherwise cutting out the metal, or in any other suitable and practicable manner. It is desirable to machine the groove 12, but this is not necessary in the groove 11; however, where the grooves are cut by milling tools, no further machining or finishing will be necessary.

The second step includes the making of an arcuate tongue 13 and mounting the same in the groove 11, as is shown in Figure 3. The tongue is formed of the same material as the body of the ring and is made in accordance therewith. This tongue has its inner and outer arcuate surfaces struck on arcs concentric to those of the annulus when the ring is fully compressed or closed. The tongue bridges the gap between the ends of the ring and has its free end disposed in the groove 12. The free end of the tongue may be provided with an undercut nose 14 so as to prevent biting into the back wall of the groove 12. The outer edge of the tongue may be beveled or cut off at 15 to obviate a point, which might injure the cylinder wall.

After the tongue 13 has been placed in the groove 11, as is shown in Figure 3, the inner end or extremity of the tongue is welded, brazed, or otherwise secured, to the annulus as is indicated in dotted lines in Figure 4, and this constitutes the third step. This leaves that portion of the tongue extending from the point 1'7 to the end of the annulus free from and unattached to the annulus, but lying in the groove 11 contiguous to the walls thereof, and flush with the surfaces of said annulus.

It is important that the portion of the tongue which lies in the groove 11 be in intimate contact with the walls of said groove and not separate or spaced therefrom. This coextensive contact assures a flow of heat from the tongue to the body of the ring and, therefore, a uniform heating of both the tongue and the body. It is ob vious that the length of the tongue governs the extent of its projection, and, therefore, the groove 12 and the projecting or extending portion of the tongue'may be made of any desired length. The tongue has a sliding engagement in the groove 12 and the ring operates in the usual manner.

It is pointed out that where the tongue is formed in the usual manner, which consists in cutting it from the same piece of metal as that of the annulus, there is bound to be-a rupture point at the intersection of the tongue and the annulus. In one-pjece rings made in the usual way, crystallization soon sets up and the tongue breaks off from its point of attachment to the annulus. In my invention the'tongue is resilient and may move independently of either end'of the annulus. It may undergo expansion and contraction independently of the annulus, and may be made from an entirely different metal, if desired. Such a goodly portion of the tongue overlies the walls of the groove 11 without being attached thereto as to permit the tongue tofreely move away from and toward the walls of said groove 11, when necessary. However, under all conditions the tongue, when in its normal position or in its working position, lies in contact with the walls of the grooves. When the tongue is secured in the groove, by welding or otherwise, it will have the appearance shown in Figures 5, 6 and 7.

Such a structure not only prevents breakage due to crystallization, or rupture, but also reduces breakage due to handling and installing. It will be noted that when the ring is fully compressed or closed, as is shown in Figures 6 and 7, the free end of the tongue does not engage the inner end of the groove 12. This permits the tongue to elongate when heated without buckling. The increased length of the tongue, reference being made to the portion lying between the free end of the tongue and the point 17, will give an ample opportunity for dissipation of the heat and will permit the tongue to undergo expansion and contraction in a more uniform manner.

The description which has been given, recites more or less detailof a particular embodiment of the invention, which is set forth as new and useful, however, I desire it understood that the invention is not limited to such exact details of construction, because it is manifest that changes andmodiflcations may be made, within the scope of the appended claims, without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent, is:

1. Themethod of producing piston rings which consists, in producing a split resilient annulus, then forming circumferential groves in the ends of the annulus, then producing an arcuate tongue from a separate piece of metal, and then permanently uniting one end of the tongue to the inner end of one of the grooves, whereby said end be- 1 comes an integral part of the annulus, and also whereby a substantial portion of the tongue is left unattached, but in contact with the walls of the said groove and is free to slide in the other groove. &

2. The method of producing piston rings which consists, in producing a split resilient annulus, then forming circumferential grooves in the ends of the annulus, then producing an arcuate tongue from a separate piece of metal and providing it with surfaces formed on arcs concentric to those of the annulus when the latter is fully compressed, and then permanently uniting one end of the tongue with one end of one of the grooves, whereby said tongue becomes an integral part of the annulus and has a substantial portion co-extensive with the walls of the said groove and in contact therewith but separate therefrom and is free to slide in the other groove 3. The method of producing piston rings which 111 consists, in producing a split-resilient annulus, then forming circumferential grooves in the ends of. the annulus, then producing an arcuate tongue from a separate piece of metal and providing it with surfaces formed on arcs concentric to those of the annulus when the latter is fully compressed, and then welding one end of the tongue with one end of one of the grooves, whereby said tongue becomes an integral part of the annulus and has a substantial portion coextensive with the walls of the said groove and in contact therewith but separate therefrom and is free to slide in the other groove.

WILLIAM S. BAICER. 

